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From:   Dinghao Liu <dinghao.liu@zju.edu.cn>
To:     dinghao.liu@zju.edu.cn, kjlu@umn.edu
Cc:     Bin Liu <b-liu@ti.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] usb: musb: Fix runtime PM imbalance on error
Date:   Thu, 21 May 2020 15:35:47 +0800
Message-Id: <20200521073547.18828-1-dinghao.liu@zju.edu.cn>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When copy_from_user() returns an error code, a pairing
runtime PM usage counter decrement is needed to keep
the counter balanced.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
---
 drivers/usb/musb/musb_debugfs.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 7b6281ab62ed..837c38a5e4ef 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -178,8 +178,11 @@ static ssize_t musb_test_mode_write(struct file *file,
 
 	memset(buf, 0x00, sizeof(buf));
 
-	if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+	if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) {
+		pm_runtime_mark_last_busy(musb->controller);
+		pm_runtime_put_autosuspend(musb->controller);
 		return -EFAULT;
+	}
 
 	if (strstarts(buf, "force host full-speed"))
 		test = MUSB_TEST_FORCE_HOST | MUSB_TEST_FORCE_FS;
-- 
2.17.1